A virtual private network (VPN) is a connection to a LAN that uses (tunnels through) the infrastructure of a WAN (often, the Internet). A VPN typically uses encryption and other types of security to protect data and to authenticate users.

In a PACS, a VPN can be used to extend PACS access to doctors' homes for teleradiology. VPNs are also used to provide service providers with remote access to a PACS.